Vibration at low speeds

[Bernd]

Hi there;
One my first posts here, so I'll be glad if any of you can give me some advise.
My LC is a 1997 HZJ75 (6cyl Diesel), original suspension, no previous problems with the motor.
Recently, I noticed a considerable vibration when driving less than 30Kph (that is about 18Mph).
For example, when approaching a red light, and I begin to brake, and at about 30Kph the vibration begins. Even if I loose the brake pedal, the vibration continues until the car stops.
Other example: When driving slow in heavy traffic the vibration is constant until I stop. I have to point that at high speeds (50/60/70/70 Kph) there's no vibration at all.
Some things I've already done:
- Wheels rotation and balancing (no luck)
- Checked the steering damper for loose ends (no luck)
- Changed motor mounts (no luck)
- Today, checked the universal joints of the driveshaft (cardan) and the mechanic told me they were worn, Changed them but the vibration persists.

Any help with this will be much appreciated.
Thanks!

 

[DamoPeru]

Welcome Bernd!
how old are your shock absorbers and steering damper? have your checked your engine mounts and tie rod ends?
Cheers,

Edit: sorry, I see you changed the engine mounts

 

[chappohj47]

Do you have mud tyres they do it to at about 30km an hour on mine

 

[Squash]

Check for a sticking brake caliper.
If you are lazy like me...drive normally and then use your hand to feel for heat on hub and rotor. Be careful things may be hot.

 

[dabasscow]

Have you checked the wheel bearings, king pin preload, leaf spring bushes, u-bolts tight, leaf spring clips in good order?

 

[Bernd]

Welcome Bernd!
how old are your shock absorbers and steering damper? have your checked your engine mounts and tie rod ends?
Cheers,

Edit: sorry, I see you changed the engine mounts

Thanks Damien! The shock absorbers and steering damper are a couple of years old but the mechanics told me they're Ok.

 

[Bernd]

Do you have mud tyres they do it to at about 30km an hour on mine

Hi chappohj47,
Yes, chatting with some friends, they've told me they also have vibration problems with mud tires. I'll be changing them next year and see what happens. Lately, after the changing the universal joints of the driveshaft, the vibration is less - but is still present at about 10~20Kph

 

[Bernd]

Check for a sticking brake caliper.
If you are lazy like me...drive normally and then use your hand to feel for heat on hub and rotor. Be careful things may be hot.

Hi Squash,
I've checked the front and rear brakes and they're appear to be Ok. I'll check for the heat you mention.
Thanks!

 

[Bernd]

Have you checked the wheel bearings, king pin preload, leaf spring bushes, u-bolts tight, leaf spring clips in good order?

Hi dabasscow
One of my plans is to change full suspension next year, so if the problem persists till then, I will be able to determine if the problem was suspension-related.

Thanks!

 

[DamoPeru]

Hi chappohj47,
Yes, chatting with some friends, they've told me they also have vibration problems with mud tires. I'll be changing them next year and see what happens. Lately, after the changing the universal joints of the driveshaft, the vibration is less - but is still present at about 10~20Kph

Bernd, try doing some test driving on the road with 20 psi in the tyres, then air up to 25 psi... then 30, 35, 40, etc.... if the wobble persists without change among all tyre pressures: it can't be the tyres. if the tyres are the cause, I would imagine the wobble would be significantly different at different pressures, and you may even find a pressure where it doesn't wobble. cheers

 

[dabasscow]

Good luck mate hope you get it sorted